LONDON — The seas around Britain are starting to teem with fish species once deemed exotic as climate change raises water temperatures, forcing the former dominant occupants to flee northward toward the Arctic and opening the way for those from the hotter south, according to marine and fisheries scientists.

Such is the extent of the migration already observed, which is expected to grow in coming decades and could even force a change in the country’s fish menus. Once-local species are moving farther afield and therefore becoming more expensive to catch, while formerly foreign ones become plentiful locally and therefore presumably cheaper and easier to harvest.

“People have started calling the North Sea the crucible of climate change. It has warmed by about a degree Celsius over the last 50 to 100 years, which is something like six times faster than pretty much any marine area around the world,” John Pinnegar, program director of the Marine Climate Change Centre at the government’s Centre for Environment, Fisheries and Aquaculture Science, told ClimateWire.

The “crucible of climate change”? There must be lots going on in the relatively small North Sea. The article includes the seemingly mandatory reference to climate change:

“The British have very traditional fish eating habits — historically consuming predominantly cod in the south and haddock in the north. Not many people are used to eating red mullet and sea bass. But eating habits can change, and that is partly what adapting to climate change could mean,” he added.

Wow! Think of the savings on vinegar if the seas actually were becoming acidic! They aren’t though and while the fillets may change with varying ocean currents the UK’s ubiquitous fish & chips will still be fish and chips.

I, of course, was interested in the claim the North Sea had “warmed by about a degree Celsius over the last 50 to 100 years, which is something like six times faster than pretty much any marine area around the world.”

First I went to the GISS mapmaking webpage. I used their trend analysis option for sea surface temperature data (excluded the land surface data) to see if I could confirm the claim that over the past 50 to 100 years the North Sea warmed at a rate that was six times faster than elsewhere around the global oceans. Figure 1B shows sea surface temperature anomaly trends from 1962 to 2011 (50 years). The trends in numerous places around the globe were about the same as those in the North Sea. I’ve circled the North Sea for those wondering where it is. And Figure 2 shows the 100-year trends (1912-2011). There are parts of the global oceans that have higher linear trends over the past century. Well, so much for the North Sea being “the crucible of climate change”. Oddly, Googling “the crucible of climate change” and “North Sea” in quotes provided only 46 results, with most referring to the E&E article. Others had nothing to do with the North Sea. If people have “started calling the North Sea the crucible of climate change”, they’ve been pretty secretive about it.

Figure 1B

HHHHHHHHHHH

Figure 2

Let’s take a look at the Reynolds OI.v2 sea surface temperature data. It’s a satellite-based dataset and has been available for a little more than 30 years. We’ll use the coordinates of 51N-61N, 3W-10E for the North Sea. See the map in Figure 3, which was created to show the region captured by the coordinates and to show the sea surface temperature anomalies for the week centered on June 27, 2012. Doesn’t look too warm there last week.

Figure 3

And a time series graph of North Sea data reveals a relatively high, but not astronomically high, linear trend since November 1981. It’s NOT “something like six times faster than pretty much any marine area around the world”. And the North Sea temperature data appears to have peaked already and might be on its way down.

Figure 4

Maybe the long-term data reveals something unusual. The North Sea sea surface temperature anomalies (HADISST) from January 1870 to April 2012 are shown in Figure 5. I’ve also shown the data with a 13-month running-average filter to smooth out some of the variations. Although there’s lots of variability (noise), the sea surface temperatures there are remarkably flat for the first 110+ years. Then it appears to make a quick rise starting about 1987. Figure 6 compares the linear trends before and after 1986/87.

The index of the North Atlantic Oscillation, the dominant mode of climatic variability in the North Atlantic region, changed in the late 1980s (1987–1989) from a negative to a positive phase. This led to regime shifts in the ecology of the North Sea (NS) and the central Baltic Sea (CBS), which involved all trophic levels in the pelagial of these two neighbouring continental shelf seas. Increasing air and sea surface temperatures, which affected critical physical and biological processes, were the main direct and indirect driving forces.

Under the heading of North Sea, Alheit et al (2005) write:

An ecological regime shift occurred in the North Sea ecosystem in the late 1980s that affected all trophic levels including phytoplankton, zooplankton, and benthos to fish (Reid and Edwards, 2001). It has been linked to a shift to a positive NAO index that coincided with an increased incursion of warm oceanic water from the Atlantic into the northern North Sea (Edwards et al., 2001; Reid et al., 2001a; Beaugrand, 2003).

Hmm. Let’s see. So far we’ve seen that the North Sea sea surface temperatures have increased, but the trends are not “six times faster than pretty much any marine area around the world.” We’ve seen that the recent warming has actually been tied to a shift in sea level pressure represented by the North Atlantic Oscillation, and the impacts of the naturally caused warming on sea life have also been studied for years. That raises a very basic question: why is this news?

And now for something completely different. The E&E news article also includes the following paragraph that dampens the climate change reference:

“Sea temperatures are rising — although it is hard to say whether this is a blip in geological terms or evidence of global warming. But with it we would expect to see some changes in the species distribution of fish,” said Richard Handy, director of the Ecotoxicology Research and Innovation Centre at Plymouth University’s School of Biomedical and Biological Sciences.

But then the E&E article returns to the Pinnegar interview with his discussion of climate model projections:

“The model predictions suggest that Iceland and Greenland — Greenland in particular — and Norway are probably going to benefit in terms of fisheries from climate change, at least for the next 50 to 100 years,” Pinnegar said.

I wrote an article once entitled ‘fish as a temperature proxy’ which was lodged on Climate audit. It has a lot about the changes in fish catches over the last 700 years gleaned from the records kept at Plymouth docks in South west England.(It would be good to find it again)

This photo comes from just a few miles along the coast of a place called the Pilchard Inn. its date can be clearly seen as 1336.

There are lots of places around the Devon coast associaed with Pilchards which was a favourite warm water fish for hundreds of years during the MWP but was replaced eventually by cod, or in interemdiate periods, herring.
tonyb

I found NAO has a bit of a mystery about ithttp://www.vukcevic.talktalk.net/AMOandNAO.htm
One has to ask
– How is it possible that that average N. Atlantic SST could be responding or ‘mimicking’ with years delay the long gone atmospheric pressure.
– Time delay is apparently becoming longer and longer.
(H. G. Wells time machine comes to mind)

THe North Sea is what, 10% or less of the entire world’s oceans?
================================================================
10% ?? Perhaps 0.001%. It’s that tiny stretch of water between the UK north of The River Thames and mainland Europe.

Dr. Ball, thanks for the reference, lot of stuff in there, will read it, natural climate oscillations are bit of a hobby of mine. North Hemisphere is almost reproducible (omitting the upward slope)http://www.vukcevic.talktalk.net/GSC1.htm
but the South Hemisphere is much less volatile, and totally different in the 1920-60 period.

People in the UK aren’t used to eating sea bass? Someone is eating it.
“The fish has come under increasing pressure from commercial fishing and has recently become the focus in the United Kingdom of a conservation effort by recreational anglers.” http://en.wikipedia.org/wiki/European_seabass

North Sea area is 575.200 – 750,000 square kilometers
World oceans are together 360.000.000 square kilometers

Ratio is range 5.75 to 7.5 to 3600 that is 0.15 to 0.21 %.
The North sea is about 0.15 to 0.21 % of the total ocean area with.
The average depth for the North Sea is 94 meters.
The average depth for the total global oceans is 3688 meters

the volume of the total world oceans is 1.335.000.000 km3
The volume of the North Sea is 575.200 – 750,000 square kilometers X 0.094 square kilometers = aprox 55.000 – 70.000 km3
That means that the volume of the North Sea is about 0.005 % of the total world ocean volume!

As a consultant to the US fishing industry, I say “rubbish.” The more economically-desirable species such as cod (particularly cod) become heavily over-fished, and the “exotic” species, which were likely always in the neighborhood anyway, proliferate to fill in the vacancy in the ecosystem.

We saw this in the US fishing industry in New England some years ago….cod became so heavily overfished that the boats out of Gloucester, MA had to fish for species that used to “trash species,” such as dogfish. The Gloucester fleet is but a hollow ghost of what it used to be. I expect the North Sea situation is virtually identical.

You need 20.000 North seas to fill up Earth’s oceans.
Another aspect with an average depth of 94 meters for the North Sea is that it most of the time, 90 % / during ice ages. last 2 millions years is not even there?
It should be called the Interglacial North Sea?

We’re eating less Cod & Haddock, because of dwindling stocks caused by overfishing & also the results of the EU’s disasterous Common Fisheries Policy, where even when stocks were adequate, any caught in excess of a boat’s quota, couldn’t be landed, but had to be thrown back into the sea.
Obviously, most of what gets thrown back, is dead already!

If fish species change to any extent in the North Sea there will be no great impact on the UK diet. By EU Law fishermen are only allowed to land the fish they are licenced to catch. Thus if the fisherman is licenced for mackerel and hauls in a net full of prime cod, well, he has to throw the cod (or whatever) back into the sea. The dumped fish are usually dead.
This is known as conservation of resources.

“We saw this in the US fishing industry in New England some years ago….cod became so heavily overfished that the boats out of Gloucester, MA had to fish for species that used to “trash species,” such as dogfish. The Gloucester fleet is but a hollow ghost of what it used to be. I expect the North Sea situation is virtually identical.”

The Ocean around EU has been somewhat overfished. The Oceans further North is under tight quota and net size control, Norway, Iceland, Greenland and Russia. So there is plenty Cod there.
And with Russia on our side of the table against EU it’s easier to defend this regime.

CRS, Dr.P.H. says:
July 6, 2012 at 10:31 pm
Says about overfishing in US waters here in the UK the fishermen have to contend with the common fisheries policy a wonderful invention of those sons of fun the EU. you can only catch a certain “quota” of any one species of fish if your “quota” is full you throw back “discard” those over the “quota” this protects those species under threat from overfishing? Also as all EU countries have equal rights to fish UK waters, and make fisheries policy (including land locked nations) some UK fishermen who only fished for one species of fish have found their “quota” cut to virtually zero or given “quotas” for fish that are not in the waters they fish. If fishermen land fish over their “quota” they face prosecution and fines of almost unlimited value as the fisheries department has taken a piece of law “the profits of crime act” meant to deal with drug barons etc and used it against the fishermen to take boats, houses and bank accounts.
In Norway the fishermen land all they catch and the fisheries people monitor catches and listen to what the fishermen tell them of fish stocks and close or open areas as needed giving time for stocks to increase before fishing starts again.
James Bull

Well, the most obvious reasons would be:
1. The warm Gulf Stream Current diverting more water up through the English Channel and into the North Sea than normal (the usual track is to the NW of Ireland and Scotland and up to the Norwegian coast).
2. The Siberian winter high tracking westward less often and less far than in decades/centuries gone by (this would be the most obvious means of cooling the water in winter).

Given that you can get ice in the Southern Baltic in a hard winter and the harbour at Narvik, Norway remains ice free every winter (despite its far more northerly latitude), it wouldn’t perhaps be surprising to find that the North Sea temperatures may oscillate significantly when you find that it is on the cusp of the Gulf Stream emanating from the Gulf of Mexico and the Siberian High (which produces the coldest land temperatures in the northern hemisphere pretty much).

I’ve not done the maths on the energy dissipated into the sea through cooling two or three nuclear reactors on the East Coast for about 50 years, but would it really warm the North Sea 1 degree celsius?

The period of study includes the change in 1987 and concludes:
(1) The North Sea does not show a significant trend in the mean annual SST over the past 25 years.
(2) Climatic variability occurs mainly on time scales from 5 to 10 years.
(3) Larger SST anomalies (positive or negative) are related to salinity anomalies in the eastern North Atlantic and in the North Sea.
(4) There is an indication of a change in the structure of the SST oscillation. This indication of a less stable system is also observed in global radiation at Norderney. However, both time series are too short to substantiate this feature statistically.
(5) The correlation between SST anomalies at the southern and northern inflow areas is low, suggesting different transport processes from the North Atlantic into the North Sea.
(6) SST changes are explained largely by local air–sea exchange processes, which depend on the North Atlantic atmospheric circulation. However, advective transports from the North Atlantic do play a role and probably explain part of the observed changes, especially at the entrances to the North Sea.

climatereason says:
July 6, 2012 at 2:32 pm
…
This photo comes from just a few miles along the coast of a place called the Pilchard Inn. its date can be clearly seen as 1336.

There are lots of places around the Devon coast associa[t]ed with Pilchards which was a favourite warm water fish for hundreds of years during the MWP but was replaced eventually by cod, or in interem[e]diate periods, herring.
tonyb

For those of us not up on Brit terminology, pilchards are oversize sardines. Just sayin’ …

North Sea had large number of oil platforms operating during 80-90s burning of the excess gas. The exploration has reached peak some time ago and it is now declining.
I wonder if satellite measurements can distinguish between actual SST and hot spots in the immediate atmosphere above.
Just idle speculation.

“Such is the extent of the migration already observed, which is expected to grow in coming decades and could even force a change in the country’s fish menus. Once-local species are moving farther afield …”

Yeah like on the Grand Banks. The species didn’t go anywhere, they were hauled out of the water by the world’s fishing fleets. I’m not surprised that new (smaller) species have moved in. Its not the small change in water temperature, its that the new species have moved in to fill a void where the water is full of nutrients – formerly they would have been prey for the large schools of northern fish. Any honest icthyologists out there to make a contribution.

No mystery, just a good illustration of response lagging forcing by a little less than 1/4 the cycle time when large heat capacities are involved. You get varying lag because the dominating frequency is varying. The integral takes care of this.

lgl says:
July 7, 2012 at 12:07 pm
Thanks lgl, I should have thought of that, basic physics, e.g. electric capacitor I-V relationship in an AC circuit
That opens a new avenue of research. Is there a good reference or a paper applicable to the ocean-atmosphere case?

In Norway the fishermen land all they catch and the fisheries people monitor catches and listen to what the fishermen tell them of fish stocks and close or open areas as needed giving time for stocks to increase before fishing starts again.

———-

Norway stayed out of the EU because of its outrageous Common Fisheries Policy, which AFAIK was designed to give EU countries with tiny fisheries an opportunity to ‘get even’ with the Scottish and Scandinavian and English fleets which had dominated by virtue of being maritime nations with very important traditional fisheries. The CFP used the same wording and policies as the Common Farming Policy, and the Eurocrats treated fisheries resources as being of the essential same nature as agricultural resources – which of course they are not, as the fisheries were a hunt, not crop management or animal husbandry. The emphasis was on national egalitarianism and centralized control, and nations lost control of their inshore fisheries. The latter has been a disaster for the fisheries as distant government bureaucrats generally have no understanding of the resources being managed.

Incidentally, at one time there were life-long experts in the civil service who had knowledge of the industry and the species being exploited, but governments in the 1970s moved toward a management model that saw bureaucratic managers as being interchangeable. The civil service model went from expertise and excellence to this new idea that management is the same everywhere, and so people should be moved around to different departments every 5 or so years to learn new skills and shake things up a bit. At least, that was the case in Canada and I understand that Canada was not alone in this; it is an absolute truth that the Eurocrats managing the fisheries had zero expertise.

As for the changing ocean regime, early fishery scientists were aware in the 1910s and 1920s that there were some regular temperature cycles (11 or 16 years – can’t remember which, exactly) and so the North American Council on Fishery Investigations researcher Dr. Le Danois (France) promoted the fact that fishing fleets would have to move further north in the warm years. As someone said above, fish should have fewer problems than most species in adjusting to changing temperature regimes, as many species are naturally migratory. This of course is truer of pelagic fish or northern benthic species than coral-dwellers.

Excellent commentary by many who are knowledgeable about fishery management in the EU! Your input was greatly appreciated!! Just be damn grateful that you are too far of a steam for Chinese trawlers, they don’t leave much behind.

lgl says:
July 8, 2012 at 3:15 am
Thanks for the effort, climate science will get to it one day, they are long way behind, still prattling about the insignificant CO2. I think an electric analogy could be adequate for start (Ocean = capacitor – charging with energy – releasing energy)
On the other more immediate point, by using ( what I think is) standard integration formula :
C5=C4+(A5-A3)*(B5+B3)/2 ( 3 year span: A=years, B=NAO values, C=integral)
and varying integration span from 2-6 years, I get something similar to your graph but not as good, so would be interested to know your formula.

We’re eating less Cod & Haddock, because of dwindling stocks caused by overfishing & also the results of the EU’s disasterous Common Fisheries Policy, where even when stocks were adequate, any caught in excess of a boat’s quota, couldn’t be landed, but had to be thrown back into the sea.
Obviously, most of what gets thrown back, is dead already!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
From what the fishermen are saying, there’s more cod in the North Sea than for a long time. The EU are always glad for an excuse to cover up their incompetent handling of what used to be a British resource. Talk about ineptocracy.